THEORETICAL AND METHODOLOGICAL SUBSTANTIATION OF TRANSIENT ELECTROMAGNETIC SOUNDING FROM THE ARCTIC DRIFT ICE
V.S. Mogilatov1,2, P.S. Osipova1,2, A.V. Zlobinsky3
1Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russia
2Novosibirsk State University, ul. Pirogova 1, Novosibirsk, 630090, Russia
3OOO Nauchno-Tekhnicheskaya Kompaniya Zavet-Geo, ul. Voskhod 26/1, of. 56, Novosibirsk, 630102, Russia
Keywords: Marine geoelectromagnetic sounding, drift ice, circular electric dipole, vertical electric line, Born approximation, Arctic
Abstract
Marine geoelectromagnetic sounding with artificial sources is strongly hindered by the influence of a conductive seawater layer. There is only one known wide successful application of electrical prospecting in this field - Controlled Source Electromagnetic Method (CSEM). However, this method has unfortunate limitations: the need to submerge an electromagnetic probe to the bottom of a deep (more than 1000 m) sea and the great rafting (~15 km). The method is not applicable in an ice-covered sea. Deep sounding from the sea surface and, hence, from the ice surface is possible if the TM polarization field is used. This field is generated by a vertical electric line (VEL) or a circular electric dipole (CED). The former has drawbacks even when it is used at sea. At the same time, a CED is efficient in one-dimensional and three-dimensional media in frequency and time modes. We have developed a three-dimensional mathematical tool for the CED field in the Born approximation, which is quite adequate in a conductive section with deep local inhomogeneities. The research is carried out within the framework of a geophysical project using the Arctic drift ices.
DOI: 10.15372/RGG2019130
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